The ongoing development of new chip technologies in the field of light-emitting diodes (LEDs) is a major factor prompting the use of new optical elements in housing technology.
A so-called thin-film LED chip (for a more detailed description, see below) emits about 85% of its radiation from the top of the chip, that is, from a front side of a radiation-generating semiconductor layer sequence, facing away from a carrier substrate. The remaining 15% is emitted to the side, through the flanks of the semiconductor layer sequence.
A thin-film LED chip is distinguished in particular by the following characteristic features:                a reflective layer is applied to or formed on a first main face, turned toward a carrier element, of a radiation-generating epitaxial layer sequence and reflects at least a portion of the electromagnetic radiation generated in the epitaxial layer sequence back thereinto; and        the epitaxial layer sequence has a thickness in the range of 20 μm or less, particularly in the range of 10 μm.        
The epitaxial layer sequence further preferably contains at least one semiconductor layer with at least one area having an intermixing structure that ideally leads to an approximately ergodic distribution of the radiation in the epitaxial layer sequence, i.e., it has an isofar as possible ergodically stochastic scattering behavior.
A basic principle of a thin-film LED chip is described for example in I. Schnitzer et al., Appl. Phys. Lett. 63(16), Oct. 18, 1993, 2174-2176, whose disclosure content in this regard is hereby incorporated by reference.
A thin-film LED chip is, as a good approximation, a Lambertian surface emitter, and is therefore particularly well suited for use in a floodlight.
To realize an optoelectronic component employing such a thin-film LED chip and yielding a definedly narrow emission angle and the highest possible radiant power, a radiation emitted laterally at a shallow angle from the front side and the radiation emitted laterally through the flanks of the semiconductor layer sequence must be deflected as completely as possible toward the desired optical axis of the component and into the desired emission cone of the component, so that this radiation is also emitted from the component within the desired, definedly narrow angle.